1 Characteristic of geotextiles in highway engineering
1.1 Physical properties
1) Heat resistance. The melting point of geotextile fabric at room temperature is high, which can reach 260 ℃, while the temperature of asphalt material laid on-site in the process of highway construction is 150 ℃, which is much lower than the melting point of geotextile.
2) Good strength characteristics. geotextile fabric has high tensile strength, puncture strength, and tear strength due to the use of plastic fibers as raw materials and after a complex production process.
3) Good flexibility. Geotextile is made of plastic stretched into fiber filaments many times, and processed by shearing and machine preparation, which has good deformation performance, while flexible good, folding and fracture resistance.
4) Anti-aging property. In many experimental studies, the physicochemical properties of geotextile itself are affected by environmental temperature and humidity. characteristics of geotextiles are little affected by ambient temperature and humidity; and due to the stable chemical properties, they are resistant to acid, alkali, and corrosion. Alkaline, corrosion resistance, so that it is strong anti-aging properties in practical engineering applications.
5) Good asphalt adsorption. The construction sequence of geotextile laying is: first evenly spray After sprinkling asphalt mastic oil and laying geotextile, finally laying asphalt surface layer, geotextile on leach The adsorption of geotextile on the asphalt surface layer is an important factor to ensure the overall paving effect of asphalt.
1.2 Chemical properties
1) Acid and alkali resistance. Studies have shown that geotextile fabric can maintain a good original state in different acid and alkaline environments, and the related physical and chemical properties are stable.
2) Corrosion resistance. As geotextile fabric uses plastic fiber as raw material, it is an inorganic polymer synthetic material with strong anti-corrosion resistance and strong anti-corrosion to most of the redox agents.
2 The principle of the role of geotextiles in highway engineering
With the growth of highway operation period, more and more diseases are exposed, such as network cracks, potholes grooves, cracks, etc. (see Figure 1). Cracking of road surface will affect the stability and comfort of vehicle driving. In order to solve the problem of pavement cracks, the most common method is to place asphalt mixture on the original road surface. The most common method to solve the cracked pavement is to lay an asphalt mixture cover layer on the original road surface to achieve the repair effect. Due to the long-term vehicle load and periodic environmental temperature changes caused by shrinkage deformation, structural layer relative The impact of the relative displacement of the road substrate cracks quickly reflected the overlay layer, the formation of emission cracks Cracks, not only affect the safety of road traffic but also make the surface water infiltration into the road substrate, weakening Weaken the bearing capacity of the road substrate, which will lead to the settlement and deformation of the road surface after a long time.